LAMPANG - Si Sawat, one of two big faults running through the country, unleashed its power on Wednesday and Thursday, causing seven small quakes in Umphang district, Tak province.
Tinnakorn Tatong, director of the Department of Mineral Resources Regional Office 1, said in Lampang province on Thursday that the magnitudes of the quakes ranged from 2.1 to 3.6.
The magnitudes above 3.0 happened on Thursday -- 3.6 at 10.29am and 3.2 at 10.45am, said the director whose office monitors 17 provinces in the North.
Three more quakes happened later with the magnitudes of 2.1 at 2pm and 4.31pm and 2.9 at 5.23pm.
On Wednesday two quakes were recorded with the magnitude of 2.8 at 6.53am and 3.03pm.
Local people could feel the tremor which was 2-12 kilometres deep. There was neither impact nor damage, he said.
Mr Tinnakorn attributed the repeated earthquakes to Si Sawat, a big, active fault stretching from Tak province southward to Kanchanaburi, Suphan Buri and Uthai Thani.
The fault has moved and released its power several times, which is a good sign, he said. Gradual releases of power are better than less frequent, abrupt ones, which can be very powerful, he added.
Si Sawat is near the big and active Three Pagodas fault. Both faults have lately moved and released their power several times and seismic officials have been closely monitoring them.
The latest quakes with the magnitudes of over 3.0 were the strongest recorded to date this year, Mr Tinnakorn said.